| 摘要 |
PROBLEM TO BE SOLVED: To provide a focus method and a device capable of obtaining the stable focusing accuracy irrespective of a worker, and controlling the focusing accuracy as the quantitative value. SOLUTION: In a focusing device having an image sensor 5, an image pick-up object holding part, an image formation lens 4, a focal point level calculation part 7b, a test chart with a test pattern thereon, and a focusing mechanism 6, the focal point level calculation part 7b converts the image signal into the binary signal to be formed of the high level and low level using the first and thresholds, calculates the first total value by totaling the number of picture elements in the section of either high level or low level of the binary signal converted using the first threshold, calculates the second total value by totaling the number of picture elements in the section of either high level or low level of the binary signal converted using the second threshold, and calculates the difference between the first and second total values. |
